<!--单选-->
<form action="" method="post">
    <input type="radio" name="q" value="big">大美女
    <input type="radio" name = "q" value = "small"> 小美女
    <input type="radio" name="q" value="old">老美女
    <input type="submit" value="提交">
</form>
<?php
$q = isset($_POST['q'])?htmlspecialchars($_POST['q']):'';
switch ($q){
    case $q == 'big':
        echo '你选中一个大美女';
        break;
    case $q == 'small':
        echo '你选中一个小美女';
        break;
    case $q == 'old':
        echo '你选中一个老美女';
        break;
    default:
        echo 'thank you 下次再来';

}
?>
